Photographic cassette for making and storing transparencies incorporating programmed film strip with opaque reflective segments

ABSTRACT

A photographic film cassette for making and storing projectable transparencies and comprising a strip of film extending through a film gate, a supply of processing composition, and a processor for applying the processing composition to the film upon manipulation of the film in the cassette. The film strip is programmed to direct the sequence of manipulations that will expose, process, project and rewind it, and comprises chemically inert reflective portions for inhibiting the projection of blank frames.

United States Patent [1 1 {111 3,776,624 Land Dec. 4, 1973 [54] PHOTOGRAPHIC CASSETTE FOR MAKING 2,473,468 6/1949 Cooley 352/92 X AND S O TRANSPARENCIES 3,423,038 1/1969 Katzef et al 352/235 X INCORPORATING PROGRAMME!) FILM 3,641,896 2/1972 Downey et a1 95/13 STRIP WITH ()PAQUE REFLECTIVE FOREIGN PATENTS OR APPLICATIONS SEGMENTS 1,113,872 9/1961 Germany 352/92 [75] Inventor: Edwin H. Land, Cambridge, Mass.

Primary Exammer-Fred L. Braun [73] Assignee: Polaroid Corporation, Cambridge, An lohn W. Ericson v Mass.

22 Filed: June 9, 1972 1571 ABSTRACT A photographic film cassette for making and storing [211 App]' 26ll68 projectable transparencies and comprising a strip of film extending through a film gate, a supply of pro- [52] US. Cl 352/130, 352/92, 352/236 cessing composition, and a processor for applying the [51] Int. Cl G03c 11/00 processing composition to the film upon manipulation [58] Field of Search 352/72, 78 R, 92, of the film in the cassette. The film strip is pro- 352/ 130, 232, 233, 235, 236; 95/13, 89 R grammed to direct the sequence of maniuplations that will expose, process, project and rewind it, and com- [56] References Cited prises chemically inert reflective portions for inhibit- UNITED STATES PATENTS ing the projection of blank frames.

3,350,794 1l/l967 Gienapp et a]. .L 352/236 X 14 Claims, 8 Drawing Figures SUPPLY -30 t v 5 L 5| 38 38 40 i1 4-35 4 i B l 3o 3 41 2e gig/gap 27 30 i 27 4a 318 ========U= I I B n B H I I =-==|====1 1 I 440 p 7 2s l j 26 49 .6 8455 we mor l 50 29 PATENTED [1E8 41973 SHEET 1 OF 3 FIG. 2

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SHED 2 0F 3 PATENTEDUEC' mm PHOTOGRAPHIC CASSETTE FOR MAKING AND STORING 'IRANSPARENCIES INCORPORATING PROGRAMMED FILM STRIP wrru QPAQUE REFLECTIVE SEGMENTS ation of systems, especially useful for the production of motion pictures, in which the film in a cassette containing a film processor is exp'osed,yand then processed and projected in apparatus which manipulates the film to actuate the processor. Such a system is disclosed in U.

S. application for Letters Pat. Ser. No. 227,080, filed on Feb. 17, 1972 by Edwin H. Land for Photographic System For Processing and Projecting Transparencies, and assigned to the assignee of this application.

In the system described in the above-cited application, an initially sealed container of processing composition is opened, and then coated on the film as the film is wound onto a reel. The amount of processing composition is selected to be exhausted at the end of the coating process. Thus, all of the composition is appliedto the film, and dries on the film; the drying process is aided by projection of the film, with some attendant heating by the projection lamp, immediately after processing. v

In order to assure that all of the useable film is processed, but that no excess processing composition remains after processing, it is desirable to coat somewhat beyond the useful imaging region at either end. The film is exposed and projected through a film gate comprising a pair of spaced, light-baffled apertures through which the film passes in and out of an opaque housing. Those portions of the film in the gate while the camera is loaded and unloaded will be exposed to saturation, and portions beyond them will be unexposed. At both the beginning and the end of the coating operation, some unevenness of processing can be expected Thus, one might expect the usual amateur movie effect produced by a bewildering sequence of blinding white light frames interspersed with ragged dark patches both preceding and following the projected motion picture sequence. The object of this invention is to prevent the projection of blank or ragged frames before and after a motion picture sequence.

The above and other objects of the invention are attained by the construction of a novel film strip for a cassette containing a film processing system. The film strip comprises actuating and control means for directing the sequence of operations by which the film is exposed, processed, projected and rewound. Portions of the film are made of opaque, and preferably reflective, material, in regions so related to the locations of the actuating and control means that when the finished film is projected, only fully formed and completely processed frames are presented to the viewer. In accordance with a presently preferred embodiment of the invention, the opaque regions are located at either end of the film on the emulsion side; For reasons to appear, the opaque region at one endof the film strip is longer than that at the other end.

In the transparency processing and projection system described in the above-cited copending application Ser. No. 227,080, a cassette containing exposedbut unprocessed film is carried through a sequence of four operational stages. First, the film is advanced, in the direction in which it was advanced between exposures in the camera, to a point beyond the exposure termination point. This process has two significant advantages, and is used to perform an enabling step in the film processing operation. One advance is that the processing composition is always applied to the same length of film, even though the film may have been removed from the camera before all of it was exposed. That makes it possible to use up all of the processing composition supplied with the cassette by applying it to the film, thus minimizing the chances of leakage. Secondly, the construction of the film drive and projection system is simplified, because the basic operational cycle of advancing and then rewinding the film is the same whether the film is initially processed or unprocessed; for unprocessed film, as will appear, this basic cycle is simply repeated.

As fully described in the above-cited copending application Ser. No. 227,080, processing composition is applied to the film as it is rewound after the advance movement just described.

The processing operation is terminated when an aperture in the film engages a cam and valve member forming a part of the processor and moves it into a latched position in which the coating elements of the processor are disengaged from the film. The film cannot move beyond the final position of the cam and valve member until it is disengaged from that member when the film is advanced for projection; accordingly, a clutch in the drive mechanism slips at that point, and a signal is produced that causes the advance for projection to begin.

During the final rewinding operation, 'which takes place after the film has been projected, the film aperture passes the cam and valve member with clearance, and rewind does not terminate until the end of the film is reached. During that additional rewinding movement, a portion of film that had not previously passed through the film gate, and accordingly was neither exposed nor processed, is brought into position for projection the next time that the cassette is inserted in the film drive and projection system. In accordance with the invention, this region of the film strip, as well as others in the portions of the film strip beyond the usable imaging portion, are covered with opaque material to prevent the projection of blank or ragged frames.

The apparatus of the invention, and its mode of operation, will best be understood in the light of the following detailed description, together with the accompanying drawings, of various illustrative embodiments of the invention.

In the drawings,

FIG. 1 is a schematic perspective sketch of a film cassette shown in association with a film drive and projection system adapted to embody the invention;

FIG. 2 is a schematic elevational view, with parts shown in cross section and parts broken away, of the film drive and projection system of FIG. 1, taken substantially along the lines 2-2 in FIG. 1;

FIG. 3 is a schematic fragmentary perspective sketch of a portionof a cassette receiving receptacle in the film drive and projection system of FIG. 1, taken substantially along the lines 3-3 in FIG. 1;

FIG. 4 is a fragmentary schematic plan sketch, with parts broken away, of a film strip in accordance with the invention and forming a part of the cassette of FIG.

FIG. is a fragmentary schematic cross-sectional view of a portion of the film strip of FIG. 4, taken essentially along the lines 5-5 in FIG. 4;

FIG. 6 is a fragmentary schematic elevational view 0 a portion of the film strip of FIG. 4, taken essentially along the lines 66 in FIG. 4;

FIG. 7 is a schematic perspective sketch of a cassette adapted for use in accordance with the invention; and FIG. 8 is a schematic plan sketch, with parts omitted,

' parts shown in cross-section, and parts broken away, of

a film cassette adapted for use in accordance with the invention.

FIG. 1 shows the external and cooperative aspects of a system adapted to embody the invention. Except in the particular respects to be described, the system may be identical with that shown and described in the above-cited copending application Ser. No. 227,080, to which reference is made for a detailed description. Accordingly, the system will be here described only to the extent necessary for an understanding of the invention.

The basic elements of this system are a cassette 1,

adapted to be inserted in a pocket 2 formed in the outer housing 3 of a film drive and projection system generally designated 4. A strip of film in the cassette has ends connected to supply and takeup reels rotatably mounted in the housing of the cassette to move the film back and forth through a film gate in the housing, as will appear. A translucent viewing screen 5, on which projected images at times appear, is mounted at the front of the housing 3.

As best shown in FIG. 2, the pocket 2 has a floor 6 on which an'aperture plate 7 is mounted. The aperture plate 7 is adapted to extend into the cassette such as 1 and there register with the film in the cassette. Light supplied in. a manner to be described passes through the film, and thence over a path traversing a suitable framing aperture in the aperture plate 7, a cooperating recess in the floor 6, a blinder housing 8, and a conventional shutter 9, to a lens 10. As described in the abovecited copending application Ser. No. 227,080, the blinder housing receives a blinder that serves at times to close the optical path through the aperture in the aperture plate 7 and thereby assist in providing a lighttight environment for the film in the cassette, while it is being processed. The lens focuses an image of the portion of the film selected by the framing aperture on a mirror 11, whence it is reflected to the screen 5.

As shown in FIG. 1, the cassette 1 is provided with a number of light-bafl'led openings, l2, 13, 14, 15 and 16. These openings expose parts adapted to cooperate with corresponding parts of the film driveand projection system to perform various functions in the cassette. Thus, a sprocket formed on the takeup reel mentioned above is accessible through the opening 12. A similar drive sprocket formed on the supply reel is accessible through the opening 13. Projection light is at times admitted to the cassette through the opening 14. A stop can enter, to brake a snubber roll forming a part of the cassette, through the opening 15. The opening 16 serves to admit a locating pin, forming a part of the film drive and projection system, to register the presence of a cassette in the system and to enable the processing apparatus in a manner described in detail in the above-cited copending application Ser. No. 227,080.

A flange 17 is formed on the upper end of the cassette 1. This flange aids in grasping the cassette while inserting it in, or removing it from, the pocket 2. It also helps tofix the cassette in position in the film drive and projection system, by engagement with the rim of the pocket 2.

Referring to FIG. 3, parts adapted to enter the openings in the cassette 1 are adapted to enter the pocket 2 through corresponding openings in a side wall 18 of the pocket. Drive sprockets for the supply and takeup reels are adapted to enter through openings 19 and 20, respectively. A light beam for projecting enters through an opening 21. The locating pin enters through an opening 22. The snubber roll stop enters through an opening 23.

In addition to the aperture plate 7 described above, the actuating arm 24 of a normally closed electrical switch is removably mounted on the floor plate 6. This switch is adapted to be opened when a cassette is inserted in the pocket 2, to interrupt a restoring circuit that resets the apparatus to its standby condition if it is inadvertently started without a cassette in the pocket, as described in the above-cited copending application Ser. No. 227,080.

A foot pedal 25 is movably mounted in the pocket 2 to be depressed by the insertion of a cassette. The foot pedal is connected to an actuating arm extending through the floor plate 6, to release the locating pin as described in the above-cited application Ser. No. 227,080.

The photographic system'of the invention preferably makes use of a photofinishing process in which a strip of film, following exposure in the camera, is contacted with a single processing composition to form a finished transparency from the latent image or images formed on the film during its exposure. The physical construction of such film, the nature of the photosensitive coating thereon, and suitable processing compositions therefor, are described in the above-cited copending application Ser. No. 227,080. However, the physical construction of the film strip is modified in accordance with the invention in a manner next to be described.

Referring to FIG. 4, there is shown a film strip generally designated 26, which comprises a leader 27 terminating at an end formed with an aperture such as 28. The aperture 28 serves to connect that end of the film to a takeup reel, to be described.

Behind the leader, which may be in the neighborhood of 18 inches in length, there is a strip 29 of photographically useful film, upon which projectable images may be formed. The strip 29 may be, for example, approximately 45 feet in length for 8 mm film.

Following the photographically useful portion of the film is a trailer region generally designated 30. The trailer 30 terminates at another end formed with an aperture 35 by means of which that end of the film is adapted to be connected to a supply reel, to be described.

The fim 26 may comprise a base of any suitable transparent material of the kind conventionally used for film bases. On this base is applied, at least over the central portion of the photographically usable length of the film 29, an emulsion comprising a photosensitive coating, whereon a series of latent images may be formed with a camera. FIG. 4 shows that film strip from the emulsion side. The photosensitive coating is preferably of one of the forms, described in the above-cited copending application Ser. No. 227,080, which can subsequently be processed to form a projectable image on the film base.

It should be noted that the invention is not directed to the chemistry by which images are developed in a photosensitive emulsion and transferred to an image receiving stratum. However, in the practice of the invention, whether the film employed is black and white or color film, at the present time the preferred embodiment of the invention employs film of a type not requiring the removal of a negative emulsion after it is developed.

Referring again to FIG. 4, the film 26 is formed along one edge with sprocket holes such as 38 at regular intervals adapted to cooperate 'with a drive pawl, in a manner to be described, in either camera or projector, for incremental advancement of the film. The series of sprocket holes 38 adjacent the trailing end of the film may be interrupted by a first elongated sprocket hole.

39. This elongated hole 39 may span, for example, two of the sprocket holes 38. I

Further along'the film in the direction of the supply reel end, the series of sprocket holes 38 is again interrupted by a second elongated sprocket hole 40, longer than the sprocket hole.39 and, for example, spanning three of the sprocket holes 38. As will appear, the first elongated sprocket hole 39 establishes an exposure end point in the camera, whereas the second sprocket hole 40 determines a film takeup termination point in the film drive and projection apparatus to be described.

Basically, termination of film advance at the first elongated sprocket hole 39 is attained by the-use of a single drive pawl in the camera, which sequentially engages the sprocket holes '38 to advance the film by one frame length in a conventional manner. Toward the end of each such advance stroke, as is conventional, the pawl is cammed down out of engagement with the film. When the single pawl engages the elongated aperture 39, the camming down movement occurs before the film engages the leading edge of the elongated hole, and therefore the pawl may cycle repeatedly without further advance of the film. This serves to effect a termination of film advance for the purposes of exposure adjacent the end of the region of photographically useful emulsion, to alert the photographer, by the somewhat different sound produced when the pawl skips the film, that his cassette should be replaced.

The film drive and projection system is provided with a double pawl, comprising two integral pawls spaced apart by one frame length, each pawl being of the same shape as the single pawl in the camera. When the first elongated aperture 39 is encountered, the trailing pawl of the pair serves to engage the leading edge of the aperture 39 to cause the film to be advanced without interruption. For normally spaced sprocket holes 38, both of the pawls engage the film in sequential sprocket holes. However, when the second elongated sprocket hole 40 is encountered, the pawls will pass through it without film engagement, and thereby terminate film advance in the same manner as did the single pawl upon engagement of the double length sprocket hole Formed on the trailing end 30 of the film 26, beyond the exposure advance termination portion just described in the direction of the supply reel end of the film 26, is a singularity. generally designated 41 comprising a detent engaging element here shown as an aperture-42 formed in the film, adjacent which a projecting bump 43 is formed, as by pressure, heat and pressure, or the like. As best shown in FIG. 5, the singularity 41 thus comprises a hook adapted to engage a detent in the form of a process control actuating element, to be described, as the film is moved with respect to the detent in the direction of the takeup reel.

The bump 43 forming a part of the detent engaging assembly 41 in FIG. 4 projects from the film, and might be deformed, or might cause pressure marks on other parts of the film, as it is wound on the reel. To avoid that result, it is preferred to provide suitable pockets, not shown, comprising apertures formed in the trailing end 30 of the film, and spaced at suitable intervals with respect to the radius of the supply reel spool to receive the projection 43 as the film is wound onto the reel. This provision allows the film to be evenly wound on the spool, without deformation of the bump.

Formed on the leader end 27 of the film 26 is another detent engaging means, here shown as an aperture 44 in the central region of the film. This aperture serves to actuate a valve member forming a part of the processing apparatus to be described, for purposes to appear.

As suggested in FIGS. 4 and 6, two opaque regions A and B on the film 26 are formed of opaque material, preferably by securing opaque layers 45 and 46 to the film base over these regions. The layers 45 and 46 may be of identical composition. As shown in FIG. 6, the photosensitive emulsion 47 is coated on the film base 46 in any conventional manner. On the emulsion 47 is formed the opaque layer such as 45. v

The layer 45 may be formed by coating on the emulsion 47 a solution, latex or emulsion of any conventional thermoplastic resin material that will dry to a clear, transparent or translucent film adherent to the emulsion 47, sprinkling bright metal flakes, of aluminum or the like, into'the resinous coating before it is dry, and finally adding another protective coating of the clear resinous material to protect the metal flakes from the film processing composition. The latter is generally highly alkaline in nature, and would dissolve most metals in thin flake form upon contact.

Sufficient metallic flakes should be included in the coating to render the film strip both opaque and highly reflective in the coated regions. The reflective property of the coatings 45 and 46 is not essential to the practice of the invention, but is highly desirable, in that it prevents most of the projection light directed onto the opaque regions from being absorbent, and thereby heating the film strip.

Alternatively, the layers 45 and 46 may be made by securing strips of metal foil, such as aluminum foil or the like, to the emulsion 47, as by heat sealing, with a suitable adhesive, or by vacuum deposition or the like. The foil may be pretested from attack by the processing composition by coating the outer foil surface with a clear film of any suitable conventional thermoplastic resin in any conventional manner. Another feasible alternative is to form the coatings 45 and 46 of a thermoplastic film forming matnx filled with an opacifying toner or pigment, or including an opacifying dye in solution. One satisfactory pigment for this purpose is particulate carbon, such as graphite, carbon black, or the like.

The opaque coating 45 extends between ends 49 and I 50 on the leader 27. The end 49 is located somewhat behind the last portion of the film that will be projected after it has been rewound as described above. The end 50 is located past the aperture 44, in the direction of the supply reel end, just beyond the last portion of the film that will be overexposed in the film gate before the film is placed in the camera. For example, in one practical embodiment of the invention, the coating 45 was about 9 r inches long, and the end 50 was located about 4 inches from the aperture 44.

The opaque coating 46 extends between ends 51 and 52 on the trailer 30. The end 51 is placed far enough from'the exposure termination sprocket hole 39 so that the coating 46 will cover all of the portion of the film strip that is overexposed when the cassette is removed from the camera. The end 52 is located between the projection terminating sprocket hole 40 and the hook 41, in position to cover all of the film strip that may be exposed to light during projection. The coating 46 may be about 11 inches in length, and the end 52 may be about 6 54; inches from the length of the film in which the aperture 35 is formed.

FIGS. 7 and 8 show, in part fragmentarily and in part schematically, the pertinent elements of an internally programmed cassette 1 adapted for use in the system of the invention. The cassette comprises a housing formed of any suitable opaque material such as metal, plastic, or the like, and preferably manufactured in two cooperating parts. I

As shown in FIGS. 7 and 8, the housing parts comprise a base generally designated 51, comprising side walls 52 and a base plate 53. The base plate 53 extends across the base of the wall 52, and comprises one side of the housing. The walls 52 extend at least in part about the periphery of the base plate 53, and cooperate with interfitted walls 54 of a cover generally designated 55. The walls 54 overlap the corresponding segments of the walls 52 to form the sides of the housing of the cassette 1.

A cover plate 56 is formed integral with the walls 48, and completes the upper side of the housing as seen in FIGS. 7 and 8. When the cover is placed in position, it may be formed integral with the base 51 by heat sealing, or by a suitable adhesive, or the like.

The base and cover parts form, when assembled, the

end flange 17 that serves to support and locate the cassette 1 in either a camera, or in the film drive and projection system of FIG. 1.

Rotatably disposed within the cassette housing is a supply reel generally designated 57. The reel 57 is provided with an upper flange 58 and a corresponding lower flange, not shown in FIG. 8, to guide the film strip 26 as it is wound about the spool portion of the reel 57, not shown, to which the supply end 30 of the film 26 (FIG. 4) is attached.

A sprocket schematically indicated at 59 may be 7 formed integral with the reel 57 to adapt the reel to be driven about its axis of rotation. Access to the sprocket 59 may be provided through the aperture 13 in the cover plate 50 (FIG. 1), light-baffled by suitable conventional annular flanges formed in cooperating relation on the cover plate 56 and on the upper surface of the flange 58, as at 60. The lower flange of the reel 57 may be formed in a conventional manner with a cylindrical axial opening to receive a cooperating axle, not shown, formed integral with the base plate 53.

Initially, the film 26 is in its unexposed state and coiled primarily about the supply reel 57. It is shown in FIG. 8 in the position assumed as it nears the end of its movement away from' the supply reel, as toward the end of exposure in a camera, in which it is nearly exhausted from the reel 57.

In its path from the supply reel 57, the film 26 first encounters a bobulator roll 61. The film engages a portion of the periphery of the bobulator roll, as shown, and passes therefrom around a conventional idler roll 62 journalled for rotation in the housing, and thence through film processing means, to be described briefly below. In addition to the apparatus for processing the film in a manner to be described, the film processing means comprises a signal generator for producing an external condition signal on terminals schematically indicated at 63 and 64, to indicate whether or not the processing means has been actuated.

Beyond its path through the film processing means, the film 26 extends through a conventional lightbaffled aperture schematically indicated at 65 and forming a portion of a film gate in the housing. The film 26 reenters the housing through a second light-baffled aperture generally designated 66 and comprising a second portion of the film gate.

The film 26 next passes over a conventional snubber roll, generally designated 67, and finally passes to a takeup reel generally designated 68, comprising a spool portion to which the takeup reel end of the film is connected, and about which the film is wound as suggested in FIG. 8.

In addition to parts corresponding to those parts described in connection with the supply reel 57, the takeup reel comprises an external upper flange 69 protruding beyond the maximum radius of the film 26 when substantially stored on the takeup reel. On the flange 69 is formed a suitable drive sprocket 70, by means of which the film can be selectively advanced in a manner to be described.

The bobulator may be of any conventional construction suitable for the performance of the known function of isolating the film drive pawl associated with the camera, or the pawl associated with the projector, from the inertia of the supply reel 57. However, it is preferably of the form shown, in which the bobulator roll 61 is journalled on a pin 71 for rotation by the film.

The pin 71 is formed integral with a support 72 of plastic or the like. The support 72 is journalled to the base plate 53 by means of a pin 73 formed integral with the base plate, and biased by a spring 74 formed integral with the support 72. The spring 74 acts against a post 75 formed integral with the base plate 53. The bobulator roll 61 can thus both rotate about the pin 71, and move backwards and forwards in the directions of the double arrow shown in FIG. 8.

The bobulator roll responds to increases or decreases in the tension of the film 26 by temporarily shortening or lengthening the film path, respectively. Such changes in film tension are produced by the actuation of the film drive pawl, and are determined by the inertial forces exerted by the supply reel 57, together with the larger or smaller supply of film that may be on it at any given time. By that arrangement, as the film is advanced incrementally by the pawl associated with the camera or projector, it can rapidly move the bobulator roll against the spring 74 without immediately afiecting the supply reel, which can then more or less gradually allow the bobulator roll to relax while supplying the segment of film taken by the pawl.

A lighttight shield around the film gate formed by the apertures 65 and 66 is formed by a wall portion 76 formed integral with the base plate 53 and made integral with the cover plate 56 after assembly of the parts in the manner described above. An exposed chamber behind the film 26 is thus formed for the purpose of admitting projection light.

The apparatus for this purpose is conventional, and will only briefly be described. In short, it comprises a prism generally designated 77 and comprising a mirror, not shown, but disposed at 45 to'the plane of FIG. 8. As schematically indicated, the prism 77 is mounted between extensions 78 formed on the wall 76.

Light enters the cassette through the port 14 formed .in. the cover plate 56 in directions normal to the plane of FIG. 8. The mirror in the prism 77 directs this light downwardly through the film 26 in the film gate for the projection of images on the film through the lens (FIG. 2).

Also disposed in the chamber bounded by the wall member 76 and the film passing through the film gate is a conventional pressure plate 79, located between the prism and the film, and biased by spring 80 into engagement with the film. The spring 80 is supported and retained by suitably shaped extensions of the support wall 76, as shown.

' The pressure plate serves in the conventional manner to cooperate with a camera, by locating the focal plane of the film'during exposure. An aperture 81 is provided in the pressure plate 79, as schematically indicated, to pass light entering through the prism assembly 77 through a selected frame of the film 26, after the film is processed in a manner to be described. It is preferred that the aperture 81 be somewhat larger than the frame to be projected so that the aperture in the aperture plate 7 (FIGS. 2 and 3) serves as the limiting aperture bounding the projected frame.

The snubber roll 67 may also be of entirely conventional construction. As illustrated, it is provided with a hub portion schematically indicated at '82 that is adapted to protrude through the (suitably light-baffled) aperture 15 in the cover panel 50 for engagement by a stop member, comprising a part of either the camera or of the film drive and projection system, that is engaged when the film is to be incrementally advanced by a pawl for exposure or projection purposes. The cooperation between the snubber roll 67 and the takeup reel 68 is conventional, but will be briefly described.

The drive sprockets 59 and 70 of the supply and takeup reel 57 and 68, respectively, are adapted to be engaged by corresponding drive sprockets comprising a part of a camera, or of the film drive and projection apparatus described in the above-cited copending application Ser. No. 227,080. In the film drive and projection apparatus, both supply and takeup reels are adapted to be driven through slip clutches. In the camera, only a drive for the takeup reel need be provided.

This drive comprises a slip clutch connected to a sprocket driving the takeup reel drive sprocket 70, in cooperation with a drive pawl for sequentially engaging a series of the sprocket holes 38 formed in the film 26, along a portion of the edge of the film in the film gate between the apertures 65 and 66.

When the snubber roll 67 is stopped by engagement of the hub 82 as described above, operation of either the camera or of the film drive and projection system to incrementally advance the film towards the takeup reel, by engagement of a pawl with the sprocket holes in the film 26, will momentarily loosen the film from engagement with the stationary snubber roll 67 and allow the slip clutch driving the takeup reel 68 to take up that increment of the film advanced by the pawl. Between engagements of the pawl, the slip clutch prevents the takeup reel from advancing the film.

In the film drive and projection system, the snubber roll 67 is engaged only while the film is to be incrementally advanced onto the takeup reel. When the film is rewound onto the supply reel, the snubber roll 67 is disengaged and acts as an idler. As will appear, that may occur either during the processing of the film while rewinding, or during subsequent rewinding of the processed film after projection.

The film processing means, described in detail in the above-cited copending application Ser. No. 227,080, will next be briefly described, with reference to FIG. 8. As there shown, the apparatus generally comprises wall means comprising portions of, or formed integral with, the base plate 53 and the cover plate 56, which serve to guide, support and house the various elements of the processing apparatus to be described. These walls form an outer film composition containing housing generally designated 83, defining a chamber in which there is mounted an initially sealed container generally designated 84 of processing composition. The container 83 communicates with a coating nozzle generally designated 85. These elements are mounted above the plane of the film 26.

Principally located below, but in part surrounding, the film 26 is a pressure pad generally designated 86. The pressure pad is acted on by a spring generally designated 87.

The basic elements of the processing station further comprise a combined pressure pad deflection cam and nozzle closure valve member generally designated 88, and a pair of electrical contacts formed integral with the external terminals 63 and 64. The terminals 63 and 64 cooperate with the cam and valve assembly 88 in a manner to be described below to provide a signal indicating whether or not the film 26 has been processed.

More specifically, the outer container 83 comprises walls 89 formed integral with the floor plate 53 and extending upwardly therefrom in FIG. 8. The walls 89 and floor plate 53 form a container open on a side that is closed by a cover panel fragmentan'ly shown at 90 of the same general configuration as the region bounded by the walls 89 of the container 63.

The panel 90 is preferably put in place prior to assembly of the cover 56 with the base 53, and serves as a support for the top plate 56 after final assembly. As schematically indicated, the walls 89 are formed with an upper lug 9 1, and a lower ledge portion 92.

The initially sealed container 84, mounted within the outer container 83, comprises a tub-like receptacle 95, of a suitable plastic or the like, selected to resit interaction with the processing composition, or permeation thereof by ambient gases. The receptacle initially contains a charge 96 of processing composition in an adequate amount to process the film 26.

The receptacle 95 is formed on an open side with a circumscribing flange 97 adapted to fit into corresponding slots formed in the base plate 53 and the cover panel 56..As shown in FIG. 8, the flange 97 rests against a shoulder formed on the lug 91 at the upper end of the wall 89, and projects over the ledge 92 formed at the lower end of the wall 89.

The container 84 is sealed to initially contain the processing composition 96 by one end 98 of a tear-tab generally designated 99. The tear-tab 99 may be made of any suitable form of plastic material selected to resist the action of the composition 96, and to avoid interaction therewith, as well as to prevent the diffusion into the composition of gases such as oxygen, carbon dioxide, carbon monoxide, water, oxides or hydrides of sulfur or nitrogen, or the like, that might modify its composition. The end 98 is sealed to the plane surface of the flange 97 surrounding the opening formed in the receptacle 95, and within the flange area extending into the mounting recesses described above, by any suitable means such as heat sealing, by a suitable adhesive, or the like.

The tear-tab 99 extends from the end 98 sealed to the receptacle 95 back upon itself and out through an aperture 100 formed in the walls 89 to a processing composition release mechanism, not shown'but described in detail in the above-cited copending application Ser. No. 227,080.

Outside of the sealed container 84, the walls 89 define a chamber 101 into which the processing composition 96 can flow when the tear-tab 99 is partially detached from the receptacle 95. The outer chamber 101 communicates with the coating nozzle 85 by way of a downwardly converging section 102 that communicates with a downwardly converging inlet passage formed in the nozzle 85.

The coating nozzle 85 may be formed in a conventional manner, as by precision molding or the like, from a suitable thermoplastic resin selected to form a dimensionally stable and accurate molding whose working surfaces can be kept to close tolerances. The most critical of these form a plane, generally U-shaped film engaging land 103 formed on the base of the nozzle, and a doctor bar 104, lying across the bend of the U-shaped land, and recessed from it as shown in FIG. 8.

The depth to which the doctor bar is recessed is greatly exaggerated in FIG. 8; it is selected to be twice the desired thickness to which the coating composition is applied to the film 26. The film engaging land 103 and the doctor bar 104 circumscribe a generally rectangular outlet aperture formed in the nozzle and communicating with a downwardly converging passageway 106 through which the processing composition is received from the outer container 83, as described above.

The nozzle 85 is provided at the sides with posts 114 that provide guidance for the film in its path over the coating gap. These posts also serve at times to stop the nozzle closure plate portion of the element 88, to be described.

When engaged with the film in the manner to be described below, the film is adapted to pass over the nozzle outlet port and between the posts 114 with the emulsion side of the film in engagement with the land 103. During this engagement, coating takes place while the film moves, so that the emulsion surface leaves the coating aperture as it passes over the doctor bar 104 and carries with it a coating of processing composition established by the depth to which the bar 104 is recessed above the land 103.

The pressure pad 86 is shown in FIG. 8 in the initial position assumed upon assembly of the cassette and prior to processing of the film 26. As shown, the film 26 normally passes below the nozzle 85, and above a normally disengaged film engaging pad surface 116 of the pressure pad, 86. The pad surface is formed on an upwardly extending and generally rectangular protrusion in a base plate 117.

The pressure pad 86 may be made of any suitable conventional material, such as stainless steel or the like. The raised surface 1 16, formed by die stamping or the like, is ground or otherwise finished with a film engaging plane surface that is adapted to mate, through the film 26, with the plane of the land 103 of the nozzle and generally conform to the working area of the nozzle confined between the land 103 and the doctor bar 104 and encompassing the rectangular opening through which the processing composition passes.

The pressure pad 86 is formed with an end 119 that is adapted to lightly engage the base side of the film 26 in the initial position shown in FIG. 8, for purposes to appear. Formed adjacent the end 119 on the plate 117, and extending upwardly therefrom, are a pair of ears 120 adapted to extend up past the film 26 on either side and to ultimately engage the underside of the nozzle 85.

The pressure pad 86 is formed at its other end with a pair of upstanding ears 121 formed integral with the plate 1 17 and extending upwardly past the film in FIG. 8 to engage a sloping ledge 122 formed in the lower side of an extension 123 of the walls 76 and 89. The extension 123 is formed integral with the base plate 53 and joins the wall 76 defining the projection aperture.

The ears 121 initially hold the film engaging surface 116 of the pressure pad out of engagement with the film. As will appear, the ears 121 of the pressure pad also serve at times as guides for the combined pressure pad depressing cam and nozzle closure plate member 88, to be described.

The base plate 117 of the pressure pad is divided to form a pair of legs 124 which are bent downwardly somewhat in the region of the ears 121 as suggested in FIG. 8. Between the legs 124 is formed a downwardly depending hook element 125 that initially serves as a detent to hold the pressure pad 86 in an inactive position in the housing. For that purpose, the hook 125 is engaged in the initial position shown by an upwardly bent end 126 formed at the end of the spring 87.

The spring 87 comprises a base portion 127 that is cut out to clear a bearing post 128 on which the idler roll 62 is journalled. The base portion 127 is further provided with a pair of mounting apertures in which suitable fasteners, shown as a pair of screws 129, can pass for securing the base 127 to the base plate 53. From the base portion 127 a resilient spring arm 130 extends, in planes normal to the base, into engagement with the film engaging portion of the pressure pad 86, and thence to its termination 126 initially engaged with the hook 125.

The pressure pad depressing cam and nozzle closure plate member 88 will next be described. The assembly 88 comprises a plane base plate 132 formed at one end 133 to cover the outlet port in the nozzle 85, in a manner to appear, to close the nozzle when the member 88 is moved into engagement with the nozzle at the end of the processing operation.

Formed as orthogonal extensions on the sides of the base plate 132 are a pair of cams 136 and 137 that serve at times to depress the pressure pad, described above, in a manner to appear below. The cam 136 is shorter than the cam 137, to facilitate threading of the film 26 during assembly of the cassette.

Toward the left end of the plate 132, the cam 137 is formed with a normally extending arm that extends generally parallel to the plate 132 and is formed with a pair of spring arm extensions 141 and 142. These arm extensions taper away from each other towards the ends, to allow entry of a film aperture in a manner to appear.

A central portion 143 is bent upwardly and away from leg extension portions 145 of the base plate 132, to form a hook having as its upper portion the extension 143 and as its lower portions the arms 145. These hook elements initially engage a ledge portion 146 formed integral with the base plate 54 to hold the assembly 88 in the position shown. In that position, the cams 136 and 137 extend into and are guided by the ears 121, and the nozzle closing plate end 133 of the assembly 88 confronts but does not engage a downwardly sloping guide ledge 147 formed on the wall extension 123 referred to above.

The upper spring arm 141, of the hook comprising that arm and the lower arm 142 formed on the assembly 88, lightly engages the base of the film 26 in the initial position of the parts shown in FIG. 8. The upwardly bent end of the arm 141 thus serves as a unidirectional detent that is adapted to engage the aperture 44 in the film,in a manner to be described below, towards the end of the processing cycle to be described.

The cam portion 137 of the assembly 88, of metallic conducting material, cooperates with the terminals 63 and 64 to form a signal generator indicating whether or not the film 26 has been processed. For this purpose, in the initial position of the parts shown in FIG. 8 assumed before the processing cycle is started, the cam 137 bridges the terminals 63 and 64, indicating to the film drive and projection apparatus, to be described, that the film'is not processed.

At the end of the processing cycle, the assembly 88 will be carried to the right in FIG. 8, opening the circuit path between the terminals 63 and 64 to indicate that the film has been processed.

The tear-tab 99 extends out through the aperture 100 in the outer container 83 and thence over an idler 150 joumalled for rotation in the housing by means schematically shown as a bearing post 152 formed integral with the base plate 53. The tear-tab 99 passes from the idler 150 to a tear-tab release mechanism, not shown, that is enabled by the insertion of a locating pin into the opening 16 and actuated by one of a set of teeth 151 formed on the flanges of the supply reel 57 when the supply reel is first rotated clockwise in FIG. 8 after the mechanism is enabled. The tear-tab release mechanism is fully shown and described in the above-cited copending application Ser. No. 227,080.

Having described one embodiment of the cassette of I the invention, its operation will next be described in connection with FIGS. 1-8.

Referring to FIG. 8, it will be assumed that an initially unexposed strip 'of film 26 stored primarily on the supply reel 57 has been exposed in a camera, so that it has been advanced onto the takeup reel 68 to the exposure termination point determined by the first elongated sprocket hole 39 in the film (FIG. 4). The tear-tab 99 will bein the position shown in FIG. 8. A portion of the opaque layer 46 will cover that portion of the film 26 in the film gate.

Next, assume that operation continues by the insertion of the cassette into the sprocket 2 of the film drive and projection system (FIGS. 1-3). As fully described in the above-cited copending application Ser. No. 227,080, depression of the pedal 25 will cause insertion of a locating pin into the port 16 of the cassette. Entry of the locating pin will enable the tear-tab release arm to engage te teeth such as 151 formed on the supply reel 57.

Next, assume that operation is continued by further rotation of the takeup reel 68 counterclockwise, as seen in FIG. 8, to bring the film 26 farther onto the takeup reel. During this rotation, the supply reel 57 will move counterclockwise in FIG. 8, causing the teeth 151 to pass the tear-tab release arm without effective engagement therewith.

FIG. 8 shows the parts of the coating station in their initial position, which is maintained during exposure of the film and during a portion of the first increment of motion just described, from the exposure termination point toward the second termination point in which the film is substantially exhausted from the supply reel, and in which the second elongated sprocket hole 40 in FIG. 4 will be encountered. During the interval of travel between those positions, and prior thereto, the cam and nozzle closure plate assembly 88 is held in place by engagement of the arms 143 and 145 with the ledge 146, and the upper resilient arm 141 of the film engaging hook formed on the assembly 88 is lightly engaging the base of the film 26.

The pressure pad 86 is initially held in place by engagement of its book 125 with the detent 126 formed on the spring 87. In that position, th end 119 of the pressure pad 86 lightly engages the base of the film 26, and the ears 121 are in engagement with the ledge 122 formed on the wall segment 123.

The parts of the coating station will remain in the position shown in FIG. 8 until, during the further advance of the film 26 towards the takeup reel, the film engaging hook 43 approaches and engages the end 119 formed on the pressure pad 86. When that occurs, near the second termination point established by the second elongated hole 40 in the film (FIG. 4), the hook 43 will move the pressure pad to the left in FIG. 8, to a position in which the ears 121 have moved out of engagement with the ledge 122, and upwardly under the influence of the spring 87. The ears on the pressure pad 86 will come into engagement with the posts 114 forming a part of the nozzle 85, and the pressure pad 86 will swing up into engagement with the film 26 and carry the emulsion side of the film into coating engagement with the nozzle 85. The opaque region B on the film strip extends through the film the during this movement of the film.

As the pressure pad 96 is moved to the left, the detent 126 formed on the spring 87 will be disengaged by the hook 125. The purpose of the detent 126 is primar ily to prevent premature movement of the pressure pad 86 in the housing prior to its positive disengagement from the initial position shown in FIG. 8 by a hook 43.

Next, assume that the first rewind operation is begun, by rotating the supply reel 57 clockwise in FIG. 8. As described in the above-cited copending application Ser. No. 227,080, this motion will bring the hook 43 out of engagement with the end 119 of the pressure pad. The pressure pad will now urge the film .26 into coating engagement with the nozzle 85 under the influence of the spring 87.

As the film 26 moves towards the supply reel 68, a pair of teeth 151 on the supply reel will engage the teartab release arm, detaching the tear-tab 99 in part from the receptacle 95 to allow the composition 96 to flow down into coating engagement with the nozzle and the film 26. Preferably, as described in the above-cited copending application Ser. No. 227,080, the rewinding of the film is interrupted briefly, to allow the composition to fill the nozzle. During this initial movement of the film, about 8 inches of the strip including the layer 46 are moved past the coating nozzle, and may receive some processing composition. Rewinding is then resumed, and the remainder, about 3 inches, of the layer 46, will be coated with processing composition. The composition will then be uniformly coated on the useful portion of the emulsion side of the film 26 to a thickness determined by the doctor bar 104.

A doctor bar coater is preferred to other conventional forms of coaters for the purpose of coating the film, because it is inherently insensitive to changes in the viscosity of the processing composition and to changes in linear film speed with respect tothe doctor bar, over a reasonable range that makes the process relatively insensitive to these variables. In particular, as is well known in the art in other contexts, a doctor blade or doctor bar coater inherently will lay down a uniform coating of one-half the distance between the doctor bar and the coated substrate under conditions in which a uniform meniscus can be formed on the coating liquid adjacent its interface with the substrate.

The coating operation will continue until the composition 96 is substantially exhausted and the film is stored substantially all on the supply reel 68. Toward the end of that operation, the aperture 44 (FIG. 4) will approach and engage the hook finger 141 formed on the valve and cam assembly 88. The layer 45 will partially pass through the coating station, and receive the last drops of processing composition.

As the film 26 continues to move onto the supply reel, engagement of the aperture 44 in the film with the spring arm 141 will carry the film along the arm and downardly, into the bight formed between the arms 141 and 142. Further movement of the film 26 towards the supply reel will carry the cam and valve member 88 to the right of the position shown in FIG. 8, causing the spring arms 143 and 145 to disengage the ledge 146, and bringing the cams 136 and 137 into contact with the base plate 117 of the pressure pad 86 in the region of the ears 121, with the cam assembly 88 being guided by the ears 121.

During this movement, the end 133 of the cam and valve assembly 88 is guided by the ledge 147 formed on the wall extension 111 of the housing, and moves below the nozzle 85 towards the nozzle closing position. The pressure pad 86 begins to move downwardly, out of engagement with the film 26. The film is still held down out of its normal plane of movement by engagement with the bight formed between the spring arms 141 and 142.

Movement in this direction will continue to move the assembly 88 to the right, as it goes to a final position in which the end 133 of the valve assembly 88 closes the nozzle 85 and shoulders formed on the assembly 88 engage the stops 114 formed on the nozzle 85. During its movement from the position shown in FIG. 8 to the final position just described, the cam 137 disengages the terminals 63 and 64, and thus provides a signal indicating that the film has been processed.

When the film is again moved toward the takeup reel, as during projection of the processed film, the aperture 44 will disengage the arm 141, and the film will rise to its initial plane of movement, in which it is free of all of the elements of the processing apparatus, for subsequent cycles of projection and rewinding.

As described in the above-cited copending application Ser. No. 227,080, following a delay selected to permit the processing composition to affect all of the film uniformly, a projection lamp will be energized, and the film drive and projection apparatus will project the images just processed on a viewing screen while incrementally advancing the film onto the takeup reel. During the first portion of this cycle, no scene will be projected until the layer 45 passes through the film gate. The completed series of images on the .film strip will then be projected, until the layer 46 is drawn into the film gate to abruptly terminate the projected sequence.

The dual drive pawl in the film drive and projection system will advance the film past the first elongated sprocket hole 17. Film advance is terminated when the second elongated sprocket hole 18 is encountered.

Next, the supply reel 57 will be driven to rewind the film until the end of the film on the takeup reel is encountered. As the film is moved past the position in which it was stopped by the closing of the cam and valve member 88 at the end of the coating operation, the opaque portion 45 will be moved through the film gate.

When the end of the film on the takeup reel is reached, as described in the above-cited copending application Ser. No. 227,080, the cassette will be ejected for retrieval by the user. The opaque portion 45 will be left in the film gate for cooperation with the film drive and projection system when the cassette is next inserted in the pocket 2.

While the invention has been described with reference to the particular details of preferred embodi ments, many changes and variations will occur to those skilled in the art upon reading this description, and such can obviously be made without departing from the scope of the invention.

I claim:

1. A photographic film cassette, comprising an opaque housing containing a strip of film connected at its ends to supply and takeup means, each adapted to store substantially all of the film and to exchange film one with the other, means forming a film gate in said housing, said film passing over a predetermined path between said supply and takeup means and through said film gate, film processing means located in said housing adjacent said path and comprising processing means engageable with the film and effective to process said film as said film is moved along said path, means forming a first actuating element on said film adjacent the end connected to said supply means, said first actuating element engaging said processing means with said film as said film moves toward said takeup means when substantially all of said film is stored by said takeup means, first opaque means fonning a light barrier on said film over a region extending through and on one side of said film gate when said first actuating means engages said processing means, means forming a second actuating element on said film, disengaging means operated by said second actuating element as said film moves toward said supply means when substantially all of said film is stored by said supply means for disengaging said processing means from said film, and second opaque means forming a light barrier on said film over a region extending through and on either side of said film gate when said disengaging means is operated by said second actuating element.

2. The apparatus of claim 1, in which said first and second opaque means each comprise a layer of opaque material attached to said film.

3. The apparatus of claim 2, in which said opaque layer comprises particles of carbon in a thermoplastic matrix.

4. The apparatus of claim 2, in which said film comprises a photosensitive layer on one side, and in which said opaque layer overlies said photosensitive layer.

5. The apparatus of claim 4, in which said opaque layer is highly reflective on at least the side opposite said photosensitive layer.

6. The apparatus of claim 5, in which said opaque layer comprises overlapping metallic flakes in an optically transmissive thermoplastic matrix.

7. The apparatus of claim 5, in which said opaque layer comprises a laminate of metal foil attached to said photosensitive layer and a protective coating of optically transmissive thermoplastic material on said foil.

8. In combination with a film cassette comprising an opaque housing, a takeup reel and a supply reel rotatably mounted in said housing, a strip of film having a first end connected to said supply reel and a second end connected to said takeup reel, means forming a film gate in said housing, said film passing between said reels along a path through said film gate for cooperation with a camera, for exposure of said film, and with projection means, for projection of said film, said film being initially in a first position disposed primarily on said supply reel with a first portion in said film gate, and adapted to be exposed while advancing to a second position disposed primarily on said takeup reel, film processing means mounted in said housing along said path and actuatable to a position operatively engaging said film strip and to a position out of engagement with said film strip, means forming a first actuating element on said film strip adjacent one of said ends for actuating said processing means to its film engaging position when said first actuating element reaches the position of said processing means along said path, means forming a second actuating element on said film strip adjacent the other of said ends for actuating said processing means to its disengaged position when said second actuating element reaches the position of said processing means along said path, first opaque means forming a light barrier on said film strip over a region including said first portion and including a portion that is in said film gate when said second actuating element moves toward said supply reel beyond the position in which said processing means is disengaged, and second opaque means forming a light barrier on said film strip over a second region spanning said film gate when said film strip is in said second position and when said first actuating element reaches the position of said processing means along said path.

9. The apparatus of claim 8, in which said first and second opaque means each comprise a layer of opaque material attached to said film.

10. The apparatus of claim 9, in which said opaque layer comprises particles of carbon in a thermoplastic matrix.

11. The apparatus of claim 9, in which said film strip comprises a photosensitive layer on one side, and in which said opaque layer overlies said photosensitive cally transmissive thermoplastic material on said foil. 

1. A photographic film cassette, comprising an opaque housing containing a strip of film connected at its ends to supply and takeup means, each adapted to store substantially all of the film and to exchange film one with the other, means forming a film gate in said housing, said film passing over a predetermined path between said supply and takeup means and through said film gate, film processing means located in said housing adjacent said path and comprising processing means engageable with the film and effective to process said film as said film is moved along said path, means forming a first actuating element on said film adjacent the end connected to said supply means, said first actuating element engaging said processing means with said film as said film moves toward said takeup means when substantially all of said film is stored by said takeup means, first opaque means forming a light barrier on said film over a region extending through and on one side of said film gate when said first actuating means engages said processing means, means forming a second actuating element on said film, disengaging means operated by said second actuating element as said film moves toward said supply means when substantially all of said film is stored by said supply means for disengaging said processing means from said film, and second opaque means forming a light barrier on said film over a region extending through and on either side of said film gate when said disengaging means is operated by said second actuating element.
 2. The apparatus of claim 1, in which said first and second opaque means each comprise a layer of opaque material attached to said film.
 3. The apparatus of claim 2, in which said opaque layer comprises particles of carbon in a thermoplastic matrix.
 4. The apparatus of claim 2, in which said film comprises a photosensitive layer on one side, and in which said opaque layer overlies said photosensitive layer.
 5. The apparatus of claim 4, in which said opaque layer is highly reflective on at least the side opposite said photosensitive layer.
 6. The apparatus of claim 5, in which said opaque layer comprises overlapping metallic flakes in an optically transmissive thermoplastic matrix.
 7. The apparatus of claim 5, in which said opaque layer comprises a laminate of metal foil attached to said photosensitive layer and a protective coating of optically transmissive thermoplastic material on said foil.
 8. In combination with a film cassette comprising an opaque housing, a takeup reel and a supply reel rotatably mounted in said housing, a strip of film having a first end connected to said supply reel and a second end connected to said takeup reel, means forming a film gate in said housing, said film passing between said reels along a path through said film gate for cooperation with a camera, for exposure of said film, and with projection means, for projection of said film, said film being initially in a first position disposed primarily on said supply reel with a first portion in said film gate, and adapted to be exposed while advancing to a second position disposed primarily on said takeup reel, film processing means mounted in said housing along said path and actuatable to a position operatively engaging said film strip and to a position out of engagement with said film strip, means forming a first actuating element on said film strip adjacent one of said ends for actuating said processing means to its film engaging position when said first actuating element reaches the position of said processing means along said path, means forming a second actuating element on said film strip adjacent the other of said ends for actuating said processing means to its disengaged position when said second actuating element reaches the position of said processing means along said path, first opaque means forming a light barrier on said film strip over a region including said first portion and including a portion that is in said film gate when said second actuating element moves toward said supply reel beyond the position in which said processing means is disengaged, and second opaque means forming a light barrier on said film strip over a second region spanning said film gate when said film strip is in said second position and when said first actuating element reaches the position of said processing means along said path.
 9. The apparatus of claim 8, in which said first and second opaque means each comprise a layer of opaque material attached to said film.
 10. The apparatus of claim 9, in which said opaque layer comprises particles of carbon in a thermoplastic matrix.
 11. The apparatus of claim 9, in which said film strip comprises a photosensitive laYer on one side, and in which said opaque layer overlies said photosensitive layer.
 12. The apparatus of claim 11, in which said opaque layer is highly reflective on at least the side opposite said photosensitive layer.
 13. The apparatus of claim 12, in which said opaque layer comprises overlapping metallic flakes in an optically transmissive thermoplastic matrix.
 14. The apparatus of claim 12, in which said opaque layer comprises a laminate of metal foil attached to said photosensitive layer and a protective coating of optically transmissive thermoplastic material on said foil. 